1. Field of the Invention
The invention relates to an image recording apparatus comprising: a lower body portion such as a mainbody housing incorporating an image recording portion, to which a medium supply cassette accommodating a stack of recording media is detachably attached, so that the recording media is supplied one by one from the medium supply cassette such that a topmost one of the stack of the recording media is separated from the other recording media; an upper body portion such as an upper casing incorporating an image reading device, which is pivotally connected to the lower body portion; and a guide for feeding the recording medium as supplied from the medium supply cassette to the image recording portion along a pathway U-shaped sideways.
2. Description of Related Art
A conventional image recording apparatus, such as copy machine, printer, and facsimile machine, comprises a mainbody housing incorporating an image recording portion and a recording medium feeder including a feeder roller, and an upper casing incorporating an image reading device and disposed on the mainbody housing, as disclosed in JP-A-8-188294 (especially FIGS. 1 and 2). A medium supply cassette accommodating a stack of recording media such as cut paper sheets on which image is to be recorded is detachably attached to a lower portion of the mainbody housing, and the feeder roller of the recording medium feeder is rotated to sequentially separate a topmost one of the recording media stacked in the medium supply cassette from the others to feed the recording media one by one to the image recording portion.
The recording medium feeder disclosed in the above-mentioned is constructed such that the feeder roller is disposed above the medium supply cassette, and a guide which is U-shaped sideways as seen from a lateral side and disposed at the side of an end of the medium supply cassette on the downstream side in a direction of the feeding of recording medium so as to feed each recording medium in the form of a paper sheet or others while U-turning and reversing the recording medium toward an image recording portion disposed above the medium supply cassette to record an image on the recording medium fed thereto. A lower end of the U-turn guide is connected to and supported by a mainbody housing such that the U-turn guide is pivotable about a lateral shaft. When a recording medium is caught around the feeder roller or other places, the U-turn guide is turned toward the external side of the mainbody housing so as to form a wide space between the U-turn guide and the feeder roller.
Since the U-turn guide is pivotably supported only at the lower, proximal end portion thereof, the U-turn guide tends to come off of the mainbody housing when the recording medium having a resistance to being bent presses the U-turn guide while being reversed along the guide. Hence, it is required to dispose a lock mechanism in some form for locking the U-turn guide to the mainbody housing.
Requiring an unlocking mechanism, too, the above-described arrangement where the lock mechanism is provided to lock the U-turn guide to the mainbody housing leads to an increase in the number of components of the apparatus. Where the U-turn guide and the mainbody housing are formed of a synthetic resin, it may be contemplated to form the lock mechanism integrally with at least one of the U-turn guide and the mainbody housing, so as to prevent this problem. However, this complexities the configuration of a mold used for forming the U-turn guide and/or the mainbody housing.
Further, where the lock mechanism is not a well-designed one, the guide rattles every time a recording medium passes along the U-turn guide, thereby deteriorating the stability in the feeding of recording medium, that is, a recording medium may be obliquely fed, or caught to cause a jam.